How do I determine if an IOException is thrown because of a sharing violation?

I have a C# application and I want to copy a file to a new location. Some times I need to overwrite an existing file. when this happens I receive a System.IO.IOException. I want to recover from a Sharing violation but how do I determine that IOException was returned because the destination file is in use rather then some other reason? I could look for the "The process cannot access the file because it is being used by another process." message... But I don't like that idea.